The railway going through Buggleskelly was actually the old Basingstoke to Alton line in Hampshire which closed in 1932.
The brief shot of a ferry taking Will Hay across to Ireland also appears as an English Channel ferry in Alfred Hitchcock's Eine Dame verschwindet (1938).
The railway map of Northern Ireland seen is authentic, but the name Buggleskelly has been added to the dot for Lisnaskea station, without deleting the name Lisnaskea.
The "driver's cab view" along the track at the beginning of the film was actually filmed by hanging a camera out of the end of the train, then showing the resulting footage backwards: this is why the train appears to be engaging in "wrong-track" running throughout this section.